A solar thermal conversion is a collector designed to collect heat by absorbing sunlight. The term is applied to solar hot water panels, but may also be used to denote more complex installations such as solar parabolic, solar trough and solar towers or simpler installinations such as solar air heat. The more complex collectors are generally used in solar power plants where solar heat is used to generate electricity generator. The simpler collectors are typically used for supplemental space heating in residential and commercial buildings. A collector is a device for converting the energy in solar radiation into a more usable or storable form. The energy in sunlight is in the form of electromagnetic radiation from the infraded (long) to the ultraviolet (short) wavelengths. The solar energy striking the Earth's surface depends on weather conditions as well as location and orientation of the surface,but overall, it averages about 1,000 watts per square meter under clear skies with the surface directly perpendicular to the sun's rays.